From A Wiki of Ice and Fire
The Dry Deep is an "L"-shaped canyon in far eastern Essos, south of the Cannibal Sands and the Grey Waste. The Dry Deep broadly runs east to west, with the Land of the Shrykes and K'Dath to the northwest. Just north of the Dry Deep is Bonetown, where strange, aged bones from the valley are traded. At its western end, the canyon narrowly runs south along the eastern side of the Mountains of the Morn. Southeast of the Dry Deep are the Cities of the Bloodless Men. It is said the valley is entirely devoid of water and life.